Coiro V, Volpi R, Bertoni P, Marcato A, Vourna S, Bocchi R, Bianconi L, Marchesi M, Buonanno G, Chiodera P
Istituto di Clinica Medica Generale e Terapia Medica, Università di Parma, Italia.
Horm Res. 1991;36(1-2):36-40. doi: 10.1159/000182103.
Naloxone is unable to stimulate FSH and LH secretion in elderly men, suggesting a reduced endogenous opioid control of gonadotropin secretion in senescence. In the present study, we examined whether in elderly men a chronic dopaminergic stimulation with bromocriptine (5 mg/day for 7 days) modifies the gonadotropin response to naloxone (4 mg as an i.v. bolus plus 10 mg infused in 2 h). Eleven younger men (group 1, 22-40 years old) participated as controls. Twenty-two elderly men were selected from a larger population and were divided into two groups: subjects with compensated gonadal failure (normal blood testosterone and elevated gonadotropin concentrations; group 2, n = 11; 62-80 years old) and men with normal gonadal function (normal blood testosterone and gonadotropin levels; group 3, n = 11; 61-82 years old). Naloxone induced a striking LH and a slight but significant FSH increase in group 1, but was unable to change serum gonadotropin concentrations in elderly subjects of both groups 2 and 3. When experiments were repeated after bromocriptine treatment, no significant differences in LH and FSH responses to naloxone were observed in the younger subjects. On the other hand, bromocriptine restored significant gonadotropin responses to naloxone in elderly men. In fact, after bromocriptine, naloxone-induced FSH and LH increments in groups 2 and 3 were indistinguishable from those observed in group 1. These data suggest that in men age-related dopaminergic alterations may underlie the defective endogenous opioid control of gonadotropin secretion.
纳洛酮无法刺激老年男性的促卵泡激素（FSH）和促黄体生成素（LH）分泌，这表明衰老过程中内源性阿片类物质对促性腺激素分泌的控制减弱。在本研究中，我们检测了老年男性长期使用溴隐亭（5毫克/天，共7天）进行多巴胺能刺激是否会改变促性腺激素对纳洛酮（静脉推注4毫克加在2小时内输注10毫克）的反应。11名年轻男性（第1组，22 - 40岁）作为对照参与研究。从更大的人群中选取了22名老年男性，并将其分为两组：性腺功能代偿性衰竭的受试者（血液睾酮正常但促性腺激素浓度升高；第2组，n = 11；62 - 80岁）和性腺功能正常的男性（血液睾酮和促性腺激素水平正常；第3组，n = 11；61 - 82岁）。纳洛酮使第1组的LH显著升高，FSH略有但显著升高，但在第2组和第3组的老年受试者中无法改变血清促性腺激素浓度。在溴隐亭治疗后重复实验时，年轻受试者对纳洛酮的LH和FSH反应未观察到显著差异。另一方面，溴隐亭恢复了老年男性对纳洛酮的显著促性腺激素反应。事实上，使用溴隐亭后，第2组和第3组中纳洛酮诱导的FSH和LH升高与第1组中观察到的升高没有区别。这些数据表明，在男性中，与年龄相关的多巴胺能改变可能是促性腺激素分泌内源性阿片类物质控制缺陷的基础。
